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Background Arabinoxylans (AX) are polysaccharides constituted by a backbone of xyloses with arabinose substituents ester-linked to ferulic acid (FA). The arabinose to xylose ratio (A/X) in AX may vary from 0.3 to 1.1. AX form covalent gels by cross-linking of FA but physical interactions between AX chains also contribute to the network formation. The objective of this study was to investigate the rheological and microstructural characteristics of gels based on AX enzymatically modified in A/X. Results Tailored AX presented A/X ranging from 0.68 to 0.51 and formed covalent gels. Dimers of FA content and elasticity (G’) increased from 0.31 to 0.39 g kg−1 AX and from 106 to 164 Pa when the A/X in the polysaccharide decreased from 0.68 to 0.51. Atomic Force Microscopy (AFM) images of AX gels showed a sponge-like microstructure at A/X = 0.68 while at lower values, gels presented a more compact microstructure. Scanning electron microscopy (SEM) analysis of AX gels show an arrangement of different morphology, passing from an imperfect honeycomb (A/X = 0.68) to a flakes-like microstructure (A/X = 0.51). Conclusion Lower A/X values favor the aggregation of AX chains resulting in an increase in di-FA content which improve the rheological and microstructural characteristics of the gel formed.

The present work was carried out to make a comparison between the starch debranching enzyme activity and the synthesis of total carbohydrates, starch, amylose, and amylopectin in developing kernels of two sets of triticales differing in genome composition (complete and substituted triticales). The results showed that the carbohydrate and starch accumulation observed in both genotypes of triticales increased rapidly at the early stage, reaching the maximum at the medium stage and decreasing slightly or remaining relatively constant at the last stage of kernel development. At the end of the development stage, the mature grains of complete and substituted triticales accumulated 62.5 and 54.6% starch, respectively. Both sets of triticales showed the same amylose accumulation profile as well as degree of polymerization; however, at the maturity stage there was a small but significant difference between the two sets. The final polymerization values of amylose chains in mature seeds of complete and substituted t...

Lignin conveys several important and useful characteristics to starch films depending on the lignin MW, extraction procedure, and lignin botanical source. In this study, lignin was obtained from durum wheat straw through the organosolv process, followed by fractionation according to solubility in alcohol. The alcohol-soluble lignin (ASL) was then used to prepare starch–ASL films. The mechanical properties, thermal stability, water solubility, color, and antioxidant activity of the resulting films were evaluated, and the starch–ASL films were also analyzed by means of SEMand attenuated total reflection infrared spectroscopy (ATR-IR). A procedure, to incorporate ASL, was developed and used to produce homogenous surfaces in starch–ASL films; agglomerations or undissolved particles of lignin were not observed in the starch matrix at microscopic level. ASL promoted significant decrease of the tensile strength (TS) and elastic modulus (EM), but an increase of elongation at break (EB) in films. Thermal analysis of the starch–ASL films showed high resistance to thermal degradation, due to the incorporation of ASL. In addition, the starch– ASL films exhibited antioxidant activity (2,2-diphenyl-1-picrylhydrazyl [DPPH]), which increased with increasing ASL content.

The objective of this study was to evaluate the efficacy of propolis extract (PE) to reduce lipid oxidation and microbial growth on beef patties during refrigerated storage. Beef patties were manufactured by incorporating PE in 4 different treatments: (1) Control (no PE addition); (2) commercial propolis 1 (2% w/w; CP1); (3) commercial propolis 2 (2% w/w; CP2); and (4) noncommercial propolis (2% w/w; NCP). Raw patties were wrapped with polyvinyl chloride and stored at 2 °C for 8 d. Total phenolic content (TPC), free-radical scavenging activity (FRS), and polyphenolic content of the PE were evaluated using high-performance liquid chromatography (HPLC). Lipid oxidation (thiobarbituric acid-reactive substances (TBARS), conjugated dienes (CnDs), metmyoglobin (MetMb%), pH variation, and color (L*, a*, b*, C*, and h*), and microbial growth (mesophilic and psychrotrophic bacteria) of patty samples were measured. NCP treatment demonstrated the highest FRS (64.8% at 100 μg/mL), which correlated with TPC and the presence of polyphenolic compounds. Lipid oxidation (78.54%, TBARS; 45.53%, CnD; 58.57%, MetMb) and microbial mesophilic and psychrotrophic growth (19.75 and 27.03%, respectively) values were reduced by NCP treatment in refrigerated samples after 8 d. These results indicate that PE has great potential as a natural antioxidant and antimicrobial additive to extend the shelf life of beef patties.

The aim of this study was to evaluate the effect of the freezing rate and storage time on the solubility of gluten proteins and on the fermentative and rheological properties of dough as well as the bread quality. Increased storage time very significantly decreased (P

Whole white corn was ground, and lime, water and xylanase enzyme (0.05, 0.075 or 0.1% w/w) were added. Blends were extruded, dried and ground to obtain extruded nixtamalized corn flour (ENCF), which was used to make tortillas. The water absorption index and water absorption capacity (WAC) of the corn flours were determined. Viscoelastic characteristics were determined in corn masa made of extruded nixtamalized flours. Tortillas were made, and determination of moisture content and texture (cutting force and rollability) during storage was carried out. Furthermore, tortillas were evaluated by sensory evaluation. The flours containing xylanase showed significantly higher WAC (P

This work presents the fabrication and characterization of electro-sprayed core-shell particles that were composed of maize bran arabinoxylans (MBAX) with insulin in the core, and maize wastewater arabinoxylans (MWAX) with Bifidobacterium in the shell. Two concentrations of MBAX (3 and 6% w/v) and MWAX (6 and 10% w/v) were evaluated. The particles fabricated with MBAX at 6% (w/v) in the core and MWAX at 10% (w/v) in the shell were more stable, presented spherical shape and no aggregation being therefore selected to be loaded with insulin and probiotics. These particles presented a size of 2.9 mm. Scanning electron microscopy analysis of the particle cross section revealed the presence of both, a smooth (shell) and a porous (core) microstructure. Confocal laser scanning microscopy confirmed the core-shell structure of the particles and the viability of the probiotic entrapped. Gastrointestinal simulation strongly suggests that these particles are not degraded in the stomach and small intestine and that 76% of the carried insulin is released in colon. These results indicate that insulin and Bifidobacterium encapsulation by tetraaxial electro spraying can be a feasible and adequate technique to produce arabinoxylan capsules containing both insulin and probiotics. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46411.

Solutions (1 % w/v) of water-extractable arabinoxylans (WEAX) from wheat were mixed with ovalbumin solutions at different concentrations in order to obtain different protein/polysaccharide ratios (0, 0.6, 2.5, 5.0, 7.5 and 10.0). These mixtures were oxidized by a laccase (Pycnoporus cinnabarinus). The kinetics of gelation was monitored by rheological measurements of the storage modulus (G') and loss modulus (G) at 25°C during 2 h. In the different ovalbumin/WEAX mixtures, WEAX cross-linking occurred as shown by an increase in G'. However, final G' decreased as a function of protein concentration from 17.2 Pa (WEAX) to 7.1 Pa (ovalbumin/WEAX=10), following a sigmoidal relationship. Ovalbumin is probably entrapped in a WEAX covalent network, which explains the changes in rheological properties, but it does not participate in the network formation. Ferulic acid oxidation and diferulic acid formation was delayed at ovalbumin/WEAX=5.0 until 40 min but not at the end of gelation. In the same mixture SH groups from ovalbumin oxidized more rapidly than the protein alone. Ovalbumin via SH groups are probably responsible for the FA oxidation delay and the weaker WEAX gel formed by blocking the enzymatically formed free radicals.

To find the best solvent of those reported and to study changes in protein aggregation during corn processing to obtain tortillas, extractability of corn proteins with three alcoholic solutions (70% ethanol, 50% propanol, and 60% tert-butyl alcohol) was compared in corn, nixtamal, masa, and tortillas. Relative solubility was assessed through size-exclusion chromatography, SDS-PAGE, and insoluble polymeric protein determination using the Dumas procedure. Differences in the behavior of solvents in the samples indicate that different protein interactions are promoted during each of the processing steps. All the three alcoholic solutions can be used to study changes in corn proteins, but the best solvent was 50% propanol. Ethanol (70%) extracted the lowest amounts of corn proteins in tortilla process samples.